Early Chest Imaging in Patients with Puumala Hantavirus Infection

Lung ultrasonography versus chest CT for assessing peripheric pulmonary lesions in hemorrhagic fever with renal syndrome: a prospective comparative study in China

OBJECTIVES

To compare the performances of lung ultrasonography (LUS) versus chest CT for assessing peripheric pulmonary lesions in hemorrhagic fever with renal syndrome (HFRS).

METHODS

Paired LUS and chest CT scan were prospectively performed and compared when in diagnosing five pathologies including region with alveolar-interstitial pattern (RAIP), alveolar-interstitial syndrome (AIS), lung consolidation, pleural effusion (PE), and pericardial effusion, in each patient with HFRS.

RESULTS

Forty-four patients (aged 39.9 ± 15.0 years, 35 males) were included, from which 68 paired LUS and chest CT imaging data of 816 lung regions were obtained and analyzed. Compared with chest CT, LUS showed high sensitivity (92.19-100%) and negative predictive value (95.9-100%), but relatively low specificity (39.47-97.21%) and positive predictive value (37.5-76.47%) for diagnosing the above pathologies. McNemer's test showed LUS detected more positive findings than chest CT (all p ≤ 0.002). There was a strong correlation between LUS and chest CT scores (r_s = 0.7141, p < 0.0001) and both scores correlated with the disease severity, hospital days, and partial laboratory profiles in HFRS patients.

CONCLUSIONS

LUS was comparable with chest CT for diagnosing peripheric pulmonary lesions and clinical assessment in patients with HFRS. Given the high sensitivity and negative predictive value compared with chest CT, LUS can be used as an excellent rule-out tool in HFRS, while its use in rule-in still requires more evidence. Considering the obvious advantages of LUS being a bedside, less expansive, and non-radiating exam, future multi-center randomized LUS versus chest CT studies may help to guide the preferred method.

KEY POINTS

• LUS could detect more positive findings than chest CT in assessing peripheric pulmonary lesions in patients with hemorrhagic fever with renal syndrome (HFRS). • Compared with chest CT, LUS showed high sensitivity but relatively low specificity when diagnosing the peripheric pulmonary lesions caused by HFRS. • Both LUS and chest CT scores correlated with the disease severity, hospital days, and partial laboratory profiles in HFRS.

Abdominal CT findings in Puumala hantavirus-infected patients

BACKGROUND

Previous clinical studies have reported abdominal findings on ultrasonography or MRI in Puumala hantavirus-infected patients.

PURPOSE

To determine if abdominal computed tomography (CT) can lead to a diagnosis of Puumala virus infection in the presence of a suggestive clinical picture.

MATERIAL AND METHODS

CT findings were studied retrospectively in 30 patients who presented to the emergency department of two (Belgian) hospitals with serologically confirmed Puumala hantavirus infection.

RESULTS

The most frequent finding was perirenal fascial thickening (90%), followed by perirenal fat stranding (87%). Retroperitoneal fat stranding was found in 19 patients (64%) in the perivesical spaces along the fascia of the external iliac vessels with or without involvement of the presacral fat. Half of the patients had pelvic ascites, and pleural fluid was found in 7 of them. The right and left mean pole-to-pole kidney's lengths were respectively 125.7 mm and 127.8 mm in 28 patients.

CONCLUSION

Retroperitoneal fat stranding, perirenal fascial thickening and/or perirenal fat stranding were found in most patients with acute Puumala virus infection who have undergone CT. Although nonspecific, these findings may help to suggest Puumala hantavirus infection in the right clinical settings.

OUP accepted manuscript

Hantavirus-induced diseases are emerging zoonoses with endemic appearances and frequent outbreaks in different parts of the world. In humans, hantaviral pathology is characterized by the disruption of the endothelial cell barrier followed by increased capillary permeability, thrombocytopenia due to platelet activation/depletion and an overactive immune response. Genetic vulnerability due to certain human leukocyte antigen haplotypes is associated with disease severity. Typically, two different hantavirus-caused clinical syndromes have been reported: hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). The primarily affected vascular beds differ in these two entities: renal medullary capillaries in HFRS caused by Old World hantaviruses and pulmonary capillaries in HCPS caused by New World hantaviruses. Disease severity in HFRS ranges from mild, e.g. Puumala virus-associated nephropathia epidemica, to moderate, e.g. Hantaan or Dobrava virus infections. HCPS leads to a severe acute respiratory distress syndrome with high mortality rates. Due to novel insights into organ tropism, hantavirus-associated pathophysiology and overlapping clinical features, HFRS and HCPS are believed to be interconnected syndromes frequently involving the kidneys. As there are no specific antiviral treatments or vaccines approved in Europe or the USA, only preventive measures and public awareness may minimize the risk of hantavirus infection. Treatment remains primarily supportive and, depending on disease severity, more invasive measures (e.g., renal replacement therapy, mechanical ventilation and extracorporeal membrane oxygenation) are needed.